6. Pulling

As men, we tend to put a greater emphasis on the muscles we can see in the mirror, like our chest and biceps. But a strong back is fundamental to all upper body strength, and helps offset the impact a large chest can have on body posture — you don't want to look like a gorilla, do you?

Pulling exercises like rows and pull-ups use your body weight against you, and allow you to control the degree of difficulty by manipulating leverage (see video). They also happen to be two of the most primal, most functional exercises you can do, creating a larger anabolic response than isolation exercises, leading to greater gains in size and strength. If that's not motivation enough for you, know this: The trick to properly filling out a shirt is having a back to make Atlas jealous.